Added chicken and egg recursion detection

tests/core/test_SheerkaEvaluateConcept.py

@@ -1,6 +1,6 @@
 import pytest
 from core.builtin_concepts import BuiltinConcepts, ReturnValueConcept, ParserResultConcept
-from core.concept import Concept, simplec, DoNotResolve, ConceptParts, Property
+from core.concept import Concept, simplec, DoNotResolve, ConceptParts, Property, InfiniteRecursionResolved
 from parsers.PythonParser import PythonNode
 
 from tests.TestUsingMemoryBasedSheerka import TestUsingMemoryBasedSheerka
@@ -369,3 +369,91 @@ class TestSheerkaEvaluateConcept(TestUsingMemoryBasedSheerka):
         evaluated = sheerka.evaluate_concept(self.get_context(sheerka), concept)
         assert sheerka.isinstance(evaluated, BuiltinConcepts.WHERE_CLAUSE_FAILED)
         assert evaluated.body == concept
+
+    def test_i_can_detect_infinite_recursion_with_numeric_constant(self):
+        sheerka = self.get_sheerka()
+
+        one_str = Concept("one", body="1")
+        one_digit = Concept("1", body="one")
+
+        sheerka.add_in_cache(one_str)
+        sheerka.add_in_cache(one_digit)
+
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), one_digit)
+        assert evaluated.key == one_digit.key
+        assert evaluated.body == InfiniteRecursionResolved(1)
+
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), one_str)
+        assert evaluated.key == one_str.key
+        assert evaluated.body == InfiniteRecursionResolved(1)
+
+    def test_i_can_detect_infinite_recursion_with_boolean_constant(self):
+        sheerka = self.get_sheerka()
+
+        true_str = Concept("true", body="True")
+        true_bool = Concept("True", body="true")
+
+        sheerka.add_in_cache(true_str)
+        sheerka.add_in_cache(true_bool)
+
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), true_str)
+        assert evaluated.key == true_str.key
+        assert evaluated.body == InfiniteRecursionResolved(True)
+
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), true_bool)
+        assert evaluated.key == true_bool.key
+        assert evaluated.body == InfiniteRecursionResolved(True)
+
+    def test_i_can_detect_infinite_recursion_with_constant_with_more_concepts(self):
+        sheerka = self.get_sheerka()
+
+        c1 = sheerka.add_in_cache(Concept("one", body="1"))
+        c2 = sheerka.add_in_cache(Concept("1", body="2"))
+        c3 = sheerka.add_in_cache(Concept("2", body="3"))
+        c4 = sheerka.add_in_cache(Concept("3", body="one"))
+
+        for concept in (c1, c2, c3, c4):
+            evaluated = sheerka.evaluate_concept(self.get_context(sheerka), concept)
+            assert evaluated.key == concept.key
+            assert evaluated.body == InfiniteRecursionResolved(3)
+
+    def test_i_can_detect_infinite_recursion_when_no_constant(self):
+        sheerka = self.get_sheerka()
+
+        foo = sheerka.add_in_cache(Concept("foo", body="bar"))
+        bar = sheerka.add_in_cache(Concept("bar", body="baz"))
+        baz = sheerka.add_in_cache(Concept("baz", body="qux"))
+        qux = sheerka.add_in_cache(Concept("qux", body="foo"))
+
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), foo)
+        assert sheerka.isinstance(evaluated, BuiltinConcepts.CHICKEN_AND_EGG)
+        assert evaluated.body == {foo, bar, baz, qux}
+
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), bar)
+        assert sheerka.isinstance(evaluated, BuiltinConcepts.CHICKEN_AND_EGG)
+        assert evaluated.body == {foo, bar, baz, qux}
+
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), baz)
+        assert sheerka.isinstance(evaluated, BuiltinConcepts.CHICKEN_AND_EGG)
+        assert evaluated.body == {foo, bar, baz, qux}
+
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), qux)
+        assert sheerka.isinstance(evaluated, BuiltinConcepts.CHICKEN_AND_EGG)
+        assert evaluated.body == {foo, bar, baz, qux}
+
+    def test_i_can_detect_auto_recursion(self):
+        sheerka = self.get_sheerka()
+
+        foo = sheerka.add_in_cache(Concept("foo", body="foo"))
+
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), foo)
+        assert sheerka.isinstance(evaluated, BuiltinConcepts.CHICKEN_AND_EGG)
+        assert evaluated.body == {foo}
+
+    def test_i_can_manage_auto_recursion_when_constant(self):
+        sheerka = self.get_sheerka()
+
+        one = Concept("1", body="1")
+        evaluated = sheerka.evaluate_concept(self.get_context(sheerka), one)
+        assert evaluated.key == one.key
+        assert evaluated.body == 1